VANCOUVER — An imbalance in gut microbiota at baseline may be associated with the progression of Parkinson’s disease at 2-year follow-up, according to data presented at the 2017 International Congress of Parkinson’s Disease and Movement Disorders.

For the prospective study, researchers from Nagoya, Japan, aimed to establish 2-year changes in gut microbiota and serum lipopolysaccharide-binding protein levels in 36 patients with Parkinson’s disease. They also sought to determine whether gut microbiota at baseline could predict Parkinson’s disease progression at 2 years.

The researchers calculated the total number of 19 bacterial groups, genera, and species using quantitative reverse transcription polymerase chain reaction (RT-PCR) of bacterial 16S or 23S ribosomal ribonucleic acid (rRNA) at baseline and 2 years. Clinical features were quantified via the Unified Parkinson’s Disease Rating Scale (UPDRS), Mini-Mental State Examination, and Montreal Cognitive Assessment at those same 2 time points.

At follow-up, the researchers observed significant reductions in total fecal bacterial counts, Bifidobacterium, as well as theClostridium leptum subgroup, Bacteroides fragilis group, and Atopobium cluster.

The researchers also noted that increased UPDRS scores had a negative correlation with Bifidobacterium (r = 0.51; P <.05) and the Bacteroides fragilis group (r = 0.53; P <.05).

In addition, patients were evenly divided into “stable” and “deteriorated” groups, according to worsening of total UPDRS scores. Between these 2 groups, no significant difference in total bacterial counts was reported.

Notably, the “deteriorated” group had lower Bifidobacterium counts at follow-up (P <.05 after false-discovery-rate correction), although Bifidobacterium counts at baseline in Parkinson’s disease patients were comparable to controls.

“Our findings shed new light on microbiota, which have two roles [as an] initiator and promoter [of Parkinson’s disease],” the researchers concluded. “Clostridium or [short chain fatty acid]-productive bacteria were equally decreased in all previous reports.”2

As a result of the findings, the researchers noted that Bifidobacterium is unlikely to have an effect on the development of Parkinson’s disease but is likely to have a protective effect on the progression of the disease